Stubble burning, fireworks could spike Delhi AQI beginning next week

Delhi AQI today: Delhi’s air quality is deteriorating again as the capital braces for another smog season. AQI levels have fluctuated between 66 and 211 over the past week.

By: Express Web Desk

New Delhi | Updated: October 9, 2025 11:16 AM IST

3 min read

The AQI in Delhi has been fluctuating over the last seven days going up to 211, according to private air quality monitor and forecaster AQI.in.

It’s that time of the year and the national capital is bracing for a thick layer of smog in just 11 days. Every winter, residents of Delhi-NCR are choked — thanks to a host of factors such as stubble burning, vehicular pollution, and… you guessed it: Diwali crackers. Multiple studies over the last decade have shown the AQI dropping significantly in Delhi.

Moreover, hospitals have shown a marked increase in patients with breathing troubles after Diwali.

The AQI in Delhi has been fluctuating over the last seven days going up to 211, according to private air quality monitor and forecaster AQI.in. The website showed the Delhi AQI at 99 on October 3. It then went down to 77 between October 3 and 4 before rising up to 203 on October 4. The next day, the AQI was 211. On October 6, Delhi managed to improve the AQI to 92 in the evening. The AQI on October 7 recorded the best AQI of 66 in the past seven days and on October 8 the AQI went back past 100 (106).

What do these AQI numbers mean?

AQI is derived from various parameters such as particulate matter (PM) 2.5, PM 10, Carbon Monoxide (CO), Sulphur Dioxide (SO2), Nitrogen Dioxide (NO2), and Ozone (O3). Based on the readings of these parameters, a single numerical value is derived to give us an idea of whether the air that we are breathing is healthy or hazardous?

The AQI reading is categorised as follows: Good (0-50), Satisfactory (51-100), Moderately Polluted (101-200), Poor (201-300), Very Poor (301-400), and Severe (401-500). Thus, higher the AQI number, unhealthier it gets to breathe.

What is Delhi AQI today?

The Central Pollution Control Board reported an average AQI of 81 till 8 pm, Wednesday. On Thursday morning, the Air Quality Early Warning System (EWS) for Delhi, pegged the AQI at 91. The EWS forecast an AQI between 103 and 109 as the day progressed.

As per AQI.com, the Delhi AQI today had already breached the 100 mark to stand at 109 at 8 am. the difference in various AQI monitors is due to the difference in the readings at various monitoring stations in different areas. But it gives us an overall idea about the air quality in Delhi.

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The concern is more because last year, Delhi recorded the highest ever AQI of 495.

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